Missing Survey Number and not able to get self Patta to my name

My grandfather bought a 2100 sqft land from someone in 1992 with only one survey number in the land registry document. In 2019, my grand father did Dhaana Deed to me. Then i applied for join patta and verified that my name got affected in that. When i apply for self patta, i came to know that my land should have two survey numbers but in the land registry document only one survey number was there. Surveyor was asking me to add another survey number in my land registry. Then i spoke with VAO. He was asking me to survey the land with proper sqft's in each survey number. Like, Surveynumber1 = x sqft Surveynumber2 = y sqft I have done all the things. But now VAO is saying my missing survey number land patta is in some other name. So he can only do self patta transfer till the survey number which is in my land registry document and he cannot do for missing survey number land because of the patta name is in some unknown person. I actually don't now the unknown person whose name is added in my land patta for missing survey number. My grandfather also died in 2020. So i dont know that i can do Rectification Deed because grandfather is not alive and not sure that the person who give this land to my grandfather will come and sign for it? Or can i add missing survey number in patta directly by removing unknown person name. But i dont know why VAO is not helping me to do this. What i do now? Could you pl suggest?